This invention relates to molded plastic protective liners for pickup truck cargo beds, and in particular to liners with a non-skid undersurface that protects truck beds from damage due to rubbing by the liner.
Pickup trucks have been used for many years as working vehicles. In recent years pickup trucks have become increasingly popular as family transportation vehicles, because of their dual ability to haul passengers and cargo. The cargo bed surfaces of pickup trucks are generally finished with paint by the manufacturer. If the painted surfaces are unprotected, they can be scratched from cargo impact or deteriorated by weather or corrosives, seriously detracting from the value of the trucks. Whether a pickup truck is used as a working vehicle or as a family transportation vehicle, it is important to keep the surface of the cargo bed in a satisfactory condition.
Various cargo bed liners used to protect the surface of cargo beds are described in prior art patents. One-piece molded plastic truck liners comprising a front wall, opposing side walls and a bottom wall are shown in U.S. Pat. Nos. 4,341,412 to Wayne; 4,336,963 to Nix et al.; 4,181,349 to Nix et al.; 4,047,749 to Lambitz; 3,814,473 to Lorenzen; and 4,592,583 to Dresen. All of the above patents show plastic liners that fit in the truck cargo bed and bear on the bed floor, walls, and rails at various points of contact, either by design or due to irregular liner shapes and warping after the vacuum-formed manufacturing process. Where the liner meets the cargo bed there may be rubbing because one-piece molded plastic truck liners shift, particularly as the truck is being loaded and unloaded, and as cargo shifts during transport. As the liner shifts there may be rubbing on the surfaces of the truck cargo bed that can scuff, scratch, and remove paint and paint undercoats. When paint and paint undercoats are damaged, rusting of the truck bed may occur thereby exposing the truck bed to corrosion which adversely affects the appearance of the truck.
There are known truck cargo bed liners having anti-slip upper surface for restraining cargo during transport, loading, and unloading. The anti-slip surfaces comprise a layer having a higher co-efficient of friction than the plastic forming the liner. (See: U.S. Pat. No. 4,693,507, for example.) The non-slip layer may be coextruded with, adhered to, or thermally attached to the plastic base material before or during the liner vacuum forming process. Although non-slip upper surfaces in bedliners are effective for restraining cargo during transport, there is additional rubbing of the under side of the HDPE base material against the truck cargo bed because the cargo""s weight shifts the cargo and the liner to which it is now restrained.
A need exists for a one-piece plastic protective cargo bed liner for engagement with at least a portion of the truck cargo bed which will reduce damage to the cargo bed from rubbing by the liners.
The present invention is a protective truck bed liner adapted to reduce rubbing between the liner and the truck bed. The liner includes an anti-slip under layer preferably made of a plastic material that is either coextruded with or otherwise adhered to a base sheet of plastic used to vacuum form the liner.
The under layer has a coefficient of friction high enough to reduce rubbing and thereby protect the truck cargo bed by reducing damage due to the installation of the liner. The under layer can be a composition including very low density polyethylene and very high molecular weight high density polyethylene which can be in portions of about sixty percent and forty percent, respectively. The under layer may be a composition including a polyolefin and the polyolefin may be between thirty and fifty percent of the composition and is preferably about forty percent of the composition. The under layer can be as thin as a single molecular layer of anti-skid material and is preferably at least ten thousandths of an inch thick. The under layer can be uniform thickness or selectively applied to specific areas of the liner to protect cargo bed components that are more susceptible to wear.
In addition, an upper anti-slip layer can be used and it can be of the same composition as the under layer. The upper layer can be as thin as a single molecular layer of anti-skid material and is preferably at least approximately forty thousandths of an inch thick.
It is an object of the invention to provide a plastic truck cargo bed liner having an integral, durable anti-slip under layer.
It is a further object of the invention to provide a plastic protective truck cargo bed liner having an under layer that is durable.
It is an additional object of the invention to provide a plastic protective truck cargo bed liner having an anti-slip under layer joined to at least a portion of the liner under surface.